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516results about "Polyphase network asymmetry reduction" patented technology

Control method for preventing overload of transformer of energy storage system

The invention relates to the technical field of power generation, power transformation or power distribution, and discloses a control method for preventing overload of an energy storage system transformer, which comprises the following steps: monitoring the three-phase total power and the power of each phase of a power grid side ammeter in real time, and calculating the three-phase unbalance degree based on the three-phase total power when the three-phase unbalance phenomenon occurs; when the three-phase unbalance degree is greater than a preset unbalance degree threshold value, dynamically adjusting the charging power of the energy storage converter according to a starting threshold value, a charging limiting threshold value and a charging forbidding threshold value by adopting a multi-threshold value dynamic adjustment mechanism; the phase with the maximum deviation between the power of each phase and the average power of the three phases is calculated as an overload phase, load reduction is performed on the overload phase based on a load increasing and decreasing strategy, load increasing is performed on a non-overload phase, and the adjusted three-phase power is obtained; a power distribution instruction is calculated in real time in combination with a dynamic response mechanism, and the three-phase unbalance degree does not exceed a safety threshold value in cooperation with total power control. The problems of easy overload, three-phase imbalance and slow response of a transformer in the prior art are solved, and the purposes of accurate load control, high system stability and high response speed are achieved.
Owner:ZHE JIANG SAI WEI SHU ZI NENG YUAN JI SHU YOU XIAN GONG SI

Method and device for balancing neutral-point potential of three-level converter suitable for unbalanced load

The invention discloses a neutral-point potential balancing method and device for a three-level converter suitable for an unbalanced load, and belongs to the technical field of three-level converter control, and the method comprises the steps: 1, carrying out the positive and negative sequence separation of a sampling signal, and achieving the output of a three-phase balanced voltage; step 2, calculating an ideal zero-sequence component needing to be added in the modulated wave; step 3, analyzing the adjustment capability of adding the ideal zero-sequence component, and if the adjustment capability is satisfied, executing step 4; if not, skipping to step 7; 4, correcting a modulation wave symbol in the ideal zero-sequence component; 5, designing a potential regulator of the zero-sequence voltage based on the corrected modulation wave symbol; 6, performing amplitude limiting on the sum of the zero-sequence component generated by the potential regulator and the ideal zero-sequence component; step 7, carrying out midpoint balance by using an external balance circuit; and the three-level converter stops running, and the process is ended. According to the invention, neutral-point potential balance of the three-level converter is realized by adding the zero-sequence component in modulation.
Owner:XI AN JIAOTONG UNIV

Impedance scanning device based on grid-side voltage dynamic compensation under three-phase voltage unbalance working condition

The invention provides an impedance scanning device based on network side voltage dynamic compensation under a three-phase voltage imbalance working condition, and relates to the technical field of new energy station power electronic converter topology and control, the device comprises a three-phase rectifier, a direct current bus capacitor, an inverter, a voltage compensation device, a frequency sweeping device, a circuit breaker and a series transformer part, the three-phase rectifier is connected in series with inverters of the voltage compensation device and the frequency sweep device, a secondary side of a series transformer of the voltage compensation device is connected in series with a network side, a secondary side of a series transformer of the frequency sweep device is connected in series with a grid-connected point, and a primary side of the series transformer is connected to the inverters and is coupled to a secondary side of the series transformer; according to the device, the power grid side voltage is rectified through the voltage compensation unit and is compensated to the grid side after being subjected to single-stage inversion transformation, voltage compensation is achieved through the energy of a power grid when the voltage is unbalanced, and an external energy source or an interference source does not need to be introduced. After compensation, the accuracy of the frequency sweeping result is obviously improved.
Owner:YUNNAN ELECTRIC POWER TESTING & RES INST (GRP) CO LTD

Three-phase imbalance compensation method and system based on negative sequence current, and medium

The invention discloses a three-phase imbalance compensation method and system based on negative sequence current and a medium, and relates to the technical field related to power imbalance compensation, and the method comprises the steps: executing the three-phase current, voltage and reactive power data collection of a power distribution network, and carrying out the three-phase imbalance recognition through negative sequence current analysis; carrying out additional acquisition of a load mode and environment data on the power distribution network; taking the data acquisition result and the additional data set as input data to execute negative-sequence current change trend prediction; a double-layer compensation device is configured for cooperative control optimization; power distribution network balance compensation is executed through a time sequence compensation strategy, and time sequence window feedback is established; and carrying out adaptive strategy correction. The technical problems that in the prior art, a three-phase imbalance compensation strategy lacks perspectiveness and self-adaptive capacity and cannot cope with a dynamically-changing power grid scene, and consequently compensation precision and stability are poor are solved, and the technical effects that perspectiveness and predictive compensation is achieved, and three-phase imbalance compensation precision and stability are improved are achieved.
Owner:TIANJIN YAOYUAN SMART ENERGY TECH CO LTD

Intelligent commutation type three-phase imbalance dynamic treatment method for power distribution network

The invention discloses an intelligent commutation type three-phase imbalance dynamic treatment method for a power distribution network, relates to the technical field of power distribution network treatment, and aims to solve the problem of poor treatment effect of three-phase imbalance. By using the data mining and analysis technology, not only can the cost minimization path be calculated according to the current state, but also the future change can be pre-judged in combination with the load dynamic trend, so that the formulated switching strategy is more prospective and accurate, the generated high-dimensional mapping vector fuses the node characteristics and the neighbor node characteristics, and the switching efficiency is improved. By combining the use of a nonlinear activation function, the model can adaptively learn a load change rule, sensor equipment integrates various sensors and chips, has the functions of environment monitoring, power management and the like, and is matched with structural components to ensure the reliable operation of the device, reduce the operation and maintenance cost and difficulty and prolong the service life of the equipment.
Owner:SUQIAN POWER SUPPLY COMPANY OF JIANGSU PROVINCE POWER +2

Three-phase imbalance treatment method, device, system, equipment, medium and product

The invention provides a three-phase imbalance treatment method, device, system, equipment, medium and product, an operation optimization model is adopted, the operation optimization model relates to commutation soft switching constraints and reactive compensation constraints, and a solution for indicating actions of a reactive compensation device and a commutation soft switching is calculated by minimizing an objective function of the operation optimization model. Therefore, three-phase imbalance treatment is carried out through cooperation of the reactive power compensation device and the phase-change soft switch. Due to the addition of the commutation soft switch, the three-phase imbalance treatment response speed is greatly increased; based on the algorithm processing, the topology and commutation soft switch replaces a traditional interconnection switch to be connected between the two transformer areas of the power distribution network, so that interconnection and mutual assistance between the transformer areas can be considered in three-phase imbalance treatment; moreover, the key voltage treatment target of voltage deviation is considered in the operation optimization model, so that the voltage of the power distribution network does not exceed the allowable range of the national standard in a high-permeability distributed power supply scene.
Owner:HUNAN UNIV OF TECH

Multi-target double-sequence current injection method for power maximization output under three-phase imbalance fault

The invention discloses a power maximization output-oriented multi-target double-sequence current injection method under a three-phase imbalance fault, and the method comprises the following steps: S1, obtaining a three-phase voltage # imgabs0 # and a current # imgabs1 # of a PCC point after a fault steady state, and correspondingly obtaining a positive and negative sequence voltage # imgabs2 # and a current # imgabs3 # of the PCC point under a dq coordinate system; s2, according to the # imgabs 4 # and the # imgabs 5 #, calculating to obtain positive and negative sequence voltage # imgabs 6 # and phase angle difference # imgabs 7 # of the power grid in the current fault scene; s3, according to # imgabs8 # and # imgabs9 #, finding out positive and negative sequence current reference values of a dq axis in a 3-D lookup table; and S4, generating an inverter modulation signal through positive and negative sequence separation control according to the found dq-axis positive and negative sequence current reference values.
Owner:HUNAN UNIV

Method, system and equipment for quickly calculating three-phase unbalanced power flow of power distribution network and medium

The invention provides a power distribution network three-phase unbalanced power flow rapid calculation method, system and device and a medium, and the method comprises the steps: building a voltage correction equation set according to the voltage data of each node in the branch data of a power distribution network; solving the voltage correction equation set by using a parallel computing method to obtain a correction value of the voltage data; carrying out load flow calculation on the power distribution network based on the convergence condition of the corrected value of the voltage data; according to the method, the voltage correction equation set established according to the voltage data of each node in the branch data of the power distribution network is solved through the parallel computing technology to realize correction of the voltage data, and the convergence of the correction value of the voltage data is judged, so that the calculation accuracy of unbalanced load flow calculation of the power distribution network is improved; and rapid solving of the complex power distribution network power flow is realized.
Owner:CHINA ELECTRIC POWER RESEARCH INSTITUTE CO LTD +2

Three-phase imbalance treatment method and micro-energy regulator

The invention relates to a three-phase imbalance treatment method and a micro-energy regulator, and belongs to the technical field of power supply systems. The method comprises the steps that when a three-phase imbalance phenomenon occurs, the three-phase imbalance degree is obtained according to the maximum power deviation between phases and the total power of the three phases; when the three-phase unbalance degree is greater than a preset unbalance degree, calculating the single-phase power deviation of each phase according to the three-phase average power and the single-phase power of each phase; comparing the three-phase total power with a preset transformer area load rate, and when the three-phase total power is greater than the preset transformer area load rate, storing energy and discharging; if yes, the single-phase power deviation needs to be updated according to corresponding design requirements; for energy storage, the total discharge power or the total power absorption power of each phase is determined according to the updated single-phase power deviation, proportional gain and integral gain; and discharging or absorbing electricity for each phase until the total discharging power or the total electricity absorbing power of each phase is met. According to the invention, the phenomenon of heavy load or return of the transformer area can be reduced.
Owner:HENAN XJ INSTR

Voltage balancing device of 10KV three-element combined mutual inductor and use method of voltage balancing device

The invention discloses a voltage balancing device of a 10KV three-element combined mutual inductor and a using method of the voltage balancing device, and relates to the technical field of mutual inductors. The voltage balancing device of the 10KV three-element combined mutual inductor comprises a first mutual inductor shell, the voltage balancing device comprises a second mutual inductor shell, a voltage mutual inductor is installed in the first mutual inductor shell, and a current mutual inductor is installed in the second mutual inductor shell. The front end of the first mutual inductor shell is fixedly connected with a mutual inductor junction box, a voltage stabilizer is installed outside the first mutual inductor shell, and by means of Y-shaped connection of a secondary winding of the voltage mutual inductor and use of a circuit breaker and the voltage stabilizer, voltage balance of the voltage mutual inductor is facilitated; the Y-shaped connection can guarantee three-phase balance while providing a stable power supply, has an effect of absorbing harmonic waves, improves the power supply efficiency, avoids equipment damage caused by overload, and guarantees good operation of low-voltage power grid protection.
Owner:JIANGXI YI HU ELECTRICAL CO LTD

Energy storage type medium voltage sag and interruption treatment device and control method thereof

The invention belongs to the technical field of electric energy quality control, and provides an energy storage type medium-voltage voltage sag and interruption treatment device and a control method thereof.The energy storage type medium-voltage voltage sag and interruption treatment device is arranged between a large power grid and a load in series and comprises a series converter PCS1, a parallel converter PCS2, an energy storage module, an injection type series transformer T1, a parallel transformer T2, a bypass static switch STS and a bypass relay KM1; wherein the injection type series transformer T1 is connected with a large power grid, and the parallel transformer T2 is connected with a load; the series converter PCS1 is connected with the injection type series transformer T1 through the bypass static switch STS and the bypass relay KM1, and compensation voltage is generated in real time through the injection type series transformer T1; the parallel converter PCS2 is respectively connected with the parallel transformer T2 and the common direct current busbar; and the energy storage module is arranged on the common direct current busbar between the series converter PCS1 and the parallel converter PCS2 in parallel.
Owner:SHANDONG SHANDA HUATIAN TECH GRP CO LTD +1

Multi-line power quality management and power flow transfer device and control method

The invention discloses a multi-line electric energy quality management and power flow transfer device and a control method, the device comprises a first regulation and control module, a second regulation and control module and a shared direct current bus, and the first regulation and control module and the second regulation and control module are of a vertically symmetrical structure; the two regulation and control modules are the same in structure, a primary winding of a three-winding transformer is connected with a medium-voltage alternating-current bus, a wire outlet end of a first secondary winding of the three-winding transformer is connected with a first load through a secondary winding of a first series transformer which is connected in series, and a primary winding of the first series transformer is connected with an alternating-current end of a first three-phase inverter; a wire outlet end of a second secondary winding of the three-winding transformer is connected with an alternating current end of the three-phase rectifier; the medium-voltage alternating-current bus is connected with a second load through a secondary winding of a second series transformer which is connected in series, and a primary winding of the second series transformer is connected with the alternating-current end of the second three-phase inverter. According to the invention, the increasingly complicated power quality requirements under multiple working conditions in the power distribution network facing multi-feeder decoupling regulation and control and mutual assistance are met.
Owner:STATE GRID JIANGSU ELECTRIC POWER CO LTD SUZHOU BRANCH +2

Interconnected transformer area regulation and control method and system based on cooperation of F-SOP and phase converters

The invention discloses an interconnected transformer area regulation and control method and system based on F-SOP and phase converter cooperation. The method comprises the following steps: S1, acquiring operation parameters of a low-voltage distribution area; s2, calculating the three-phase unbalance degree and the load rate of the output power of the transformer and the voltage of each node of each phase, and judging whether the three-phase unbalance degree and the load rate are in a constraint interval; if the standard is reached, enabling the phase converter and the F-SOP not to act, and returning to S1; if not, starting the phase converter; s3, determining a first optimal action state of the phase converter, and secondarily judging whether the indexes reach the standard or not; if the standard is reached, the phase converter acts according to a first optimal state, otherwise, F-SOP is started; s4, constructing an optimal objective function of the coordinated action economy; and S5, solving the function, determining a second optimal action state of the phase converter and an F-SOP power scheduling instruction, and sending the second optimal action state and the F-SOP power scheduling instruction to the phase converter and the F-SOP. According to the invention, the problem of three-phase imbalance of the transformer in the transformer area and the problem of light and heavy loads are effectively solved, and meanwhile, the problem of three-phase imbalance of the transformer area line is solved.
Owner:SOUTH CHINA UNIV OF TECH

Three-phase imbalance phase-change switch switching control system based on graph neural network

The invention discloses a three-phase imbalance phase-change switch switching control system based on a graph neural network, and relates to the technical field of phase-change switch control. In order to solve the problems that in the prior art, deep analysis of load dynamic association and time sequence laws is lacked, so that a control strategy lags behind, switching actions are frequent, the treatment effect is limited, instruction time delay is large, the packet loss rate is high, and accurate synchronization of a commutation moment is difficult to guarantee. According to the method, the accuracy and efficiency of load characteristic analysis are greatly improved by constructing the load association graph structure and identifying the dynamic association mode, the graph neural network is utilized to extract the space-time sequence characteristics of the power grid topology and the load change, and the multi-dimensional and refined optimization of the commutation strategy is realized in combination with the multi-target optimization model, so that the method is suitable for large-scale popularization and application. The Mesh self-organizing network based on the power TD-LTE private network ensures that the instruction can be synchronized in millisecond and accurately sent to the phase-change switch, and provides a solid communication guarantee for effective execution of the strategy.
Owner:SUQIAN POWER SUPPLY COMPANY OF JIANGSU PROVINCE POWER +2

Three-phase imbalance control method and device for transformer area flexible interconnection system and medium

The invention belongs to the technical field of power grid control, and relates to a transformer area flexible interconnection system three-phase imbalance control method and device and a medium. Taking the transformer area converter controlled by the PQ control algorithm as a target transformer area converter; collecting a first control parameter output by an active power PI controller of the target transformer area converter; based on the upper and lower limits of the voltage target value of the DC bus, performing amplitude limiting setting on the first control parameter of the target transformer area converter to obtain the voltage target value; subtracting the voltage target value from the actual voltage value of the direct-current bus, inputting the difference value into the PI controller, and outputting a second control parameter of the target transformer area converter; taking the second control parameter as a direct-axis current target value, subtracting the direct-axis current target value from a direct-axis current actual value, and taking the difference value as the input of a direct-axis current PI controller; and controlling the target transformer area converter based on the voltage modulation signal output by the PQ control framework. The scheme can effectively improve the power supply reliability of the power distribution area and stabilize the DC bus voltage.
Owner:STATE GRID (SUZHOU) URBAN ENERGY RES INST CO LTD

Operation and maintenance method and apparatus for severe overload and three-phase imbalance of distribution transformer, and medium

Disclosed in the present invention are an operation and maintenance method and apparatus for severe overload and three-phase imbalance of a distribution transformer, and a medium. The method comprises: by quantifying the degree of difference between devices as the distance between two points, performing clustering analysis on an operation and maintenance state of a distribution transformer, so as to obtain a classification result; and on the basis of a short-term single-phase severe overload category and a short-term three-phase severe overload category in the classification result, establishing a multi-objective optimization model and solving same, so as to obtain a multi-objective optimization result, and on this basis, formulating a day-ahead source-load distribution transformer operation and maintenance plan and performing operation and maintenance control on a distribution network. The present invention provides an operation and maintenance method and apparatus for severe overload and three-phase imbalance of a distribution transformer, and a medium. Solving a multi-objective optimization model to obtain a multi-objective optimization result can ensure that operational risks caused by three-phase imbalance are reduced while balancing three-phase loads, such that differentiated operation and maintenance can be achieved by means of a day-ahead source-load distribution transformer operation and maintenance plan, thereby solving the problem of difficulty in managing severe overload and three-phase imbalance of a distribution transformer to formulate a targeted operation and maintenance plan.
Owner:GUANGDONG POWER GRID CO LTD +1

Photovoltaic inverter electric energy quality comprehensive control method and system

The invention discloses a photovoltaic inverter electric energy quality comprehensive control method and system, and the method comprises the steps: obtaining an inverter access point voltage amplitude value, calculating a three-phase voltage mean value and the deviation of each phase voltage, and obtaining an inverter three-phase output active power value; performing three-phase imbalance compensation according to the active power value, and judging whether the three-phase voltage is balanced or not; if the balance is reached, the deviation between the line voltage value after the three-phase imbalance compensation and the upper and lower limit voltage values of the power grid is calculated, the three-phase output reactive power value of the inverter is obtained, and the line voltage is adjusted according to the reactive power value; the method comprises the following steps: adjusting a line voltage, obtaining an inverter access point line load current, calculating a three-phase harmonic current compensation value, carrying out line harmonic current compensation according to the three-phase harmonic current compensation value, and realizing inverter power quality comprehensive control and high-quality power supply based on the adjusted line voltage and the compensated line harmonic current.
Owner:NARI TECH CO LTD +3

Concentrator with electrical equipment state monitoring function

The invention relates to the technical field of power monitoring, in particular to a concentrator with an electrical equipment state monitoring function. Obtaining an unbalance degree according to the state characteristic values among the three phases; clustering is carried out according to the unbalance degree of all historical moments, and distribution intensity is obtained according to interval characteristics of different moments in a moment cluster; obtaining a data similarity according to the unbalance degree in the time cluster; obtaining reference credibility according to the moment quantity characteristics, the distribution intensity and the data similarity in the moment cluster; according to the difference characteristic of the unbalance degree corresponding to the current moment and the reference moment cluster and the reference credibility of the reference moment cluster, obtaining the abnormity degree; and obtaining an anomaly trend value according to the anomaly degree of the adjacent historical time period of the current moment. The early warning index of the current moment is obtained according to the abnormity degree and the abnormity trend value, and early warning is carried out, so that the monitoring accuracy of the concentrator on the power utilization state of the electrical equipment is improved.
Owner:SHANDONG DEYUAN POWER TECHNOLOGY CORP LTD

Unbalanced load compensation method for three-phase four-wire three-level converter

The invention discloses an unbalanced load compensation method for a three-phase four-wire three-level converter. According to the method, a three-phase four-wire system three-level converter bridge arm voltage mathematical model is established based on sine carrier in-phase laminated modulation, and harmonic content analysis is completed; an SOGI-pro module is established (an error integration link is added at the input front end of a D axis of an SOGI filter, and D and Q axis second-order band-pass filters are transformed into third-order band-pass filters), so that the positive and negative sequence separation precision of three-phase unbalanced load voltage is improved. According to the method, the order of the SOGI filter is improved by reasonably designing a closed-loop transfer function, and the filtering effect of the SOGI filter in high and low frequency bands is enhanced. And a sequence-dividing imbalance compensation control loop is designed based on the three-sequence dq0 coordinate system, so that zero-static-error tracking of a positive-sequence fundamental component and powerful suppression of negative-sequence and zero-sequence imbalance components are realized. According to the invention, the accuracy of traditional positive and negative sequence separation is improved, so that the unbalanced load compensation effect under sequence separation control can be improved.
Owner:ZHEJIANG UNIV

Three-phase unbalanced power flow line loss analysis method, system, equipment and medium

The invention discloses a three-phase unbalanced power flow line loss analysis method, which comprises the following steps of: establishing a power flow model of a three-phase unbalanced system based on a sequence component method; the power flow model comprises admittance matrixes respectively corresponding to a positive sequence, a negative sequence and a zero sequence, and equivalent admittance corresponding to any two of the positive sequence, the negative sequence and the zero sequence; converting the power flow model, and determining a first relational expression among the coupled positive sequence current, the equivalent admittance and the uncoupled positive sequence current, and a second relational expression among the coupled negative sequence current, the equivalent admittance and the uncoupled negative sequence current; determining a positive sequence electrical component according to the first relational expression, and determining a negative sequence electrical component according to the second relational expression; and determining the line loss of the three-phase unbalanced system according to the positive sequence electrical component and the negative sequence electrical component. According to the method provided by the invention, the accuracy of line loss analysis can be improved.
Owner:CHINA SOUTHERN POWER GRID COMPANY

Line loss reduction method and device based on three-phase load adjustment, equipment and medium

The invention discloses a line loss reduction method and device based on three-phase load adjustment, equipment and a medium, and the method comprises the steps: collecting a three-phase load current corresponding to a power transmission line in response to a loss reduction request, and constructing a load square-time curve; creating a line loss change objective function according to a load square-time curve; calculating the minimum value of the line loss change objective function under the load constraint, and determining an adjustment load; and adjusting the three-phase load current according to the adjustment load to reduce the line loss of the power transmission line. Therefore, line loss calculation can be accurately carried out for continuous and changing three-phase load current, and the accuracy of line loss management and control is effectively improved.
Owner:FOSHAN POWER SUPPLY BUREAU GUANGDONG POWER GRID +1

System level phase unbalancing to improve overall data center sustainability

Disclosed embodiments provide methods, systems, and computer program products for implementing enhanced phase power load balancing of a set of systems (e.g., the set of systems of a data center) using a subset of the systems. Disclosed embodiments extract phase currents of a three-phase power source of the set of systems, and determine, based on extracted phase currents for the set of systems, input phase power load balancing for the subset of the systems. Disclosed embodiments alter the current input phase power balancing of the subset, unbalancing the input phase power load for the subset of the systems to provide enhanced phase power load balancing of the set of systems. Altering the current input phase power balancing for the subset of the systems can be implemented by power shifting between power supply units (PSUs), phase rotations, or input phase switching of power distribution unit (PDU) switchable output ports.
Owner:INTERNATIONAL BUSINESS MACHINE CORPORATION

Active and reactive comprehensive oscillation quantity minimization cooperative control method under current constraint condition

The invention discloses an active and reactive comprehensive oscillation quantity minimization cooperative control method under a current constraint condition, and the method comprises the steps: analyzing an inverter side current converter in a power grid voltage imbalance state, and quantifying the frequency doubling fluctuation quantity of active power and reactive power caused by a negative sequence component; a third harmonic voltage compensation method is adopted to suppress negative sequence current, the third harmonic voltage compensation amount of the converter is dynamically adjusted, and three-phase current balance is regulated and controlled; on the basis of active and reactive power fluctuation suppression of a negative-sequence current compensation method, an optimization function with the purpose of minimizing the comprehensive fluctuation quantity of active power and reactive power is constructed by utilizing controllable negative-sequence current compensation quantity and eliminating frequency doubling fluctuation quantity of active power and reactive power, and an optimal negative-sequence current compensation scheme is solved in real time by adopting a particle swarm optimization algorithm. Cooperative suppression of three-phase current balance and power oscillation is achieved, and the operation stability and the power transmission capacity of the inverter side converter under an asymmetric fault are remarkably improved under the current amplitude limiting condition.
Owner:HUANENG POWER INT ENERGY DEV CO LTD +2

Unbalance regulation and control method and system for power distribution area

The invention discloses a method and a system for regulating and controlling imbalance of a power distribution area, which are used for solving the technical problem of poor operation stability of the power distribution area caused by a traditional method for regulating and controlling imbalance of the power distribution area. The method comprises the following steps: acquiring three-phase bus voltage and three-phase current of a power distribution area; generating a power distribution area three-phase component voltage and a power distribution area power optimization objective function according to the power distribution area three-phase bus voltage and the power distribution area three-phase current; solving the power optimization objective function of the power distribution area, and outputting predicted power of the power distribution area; calculating a three-phase reference current of the power distribution area based on the predicted power of the power distribution area and the three-phase component voltage of the power distribution area; and according to the three-phase reference current of the power distribution area, generating a power distribution area imbalance regulation and control signal.
Owner:ZHANJIANG POWER SUPPLY BUREAU OF GUANGDONG POWER GRID CO LTD

Method and equipment for maintaining three-phase balance of grid-connected point voltage under unbalanced disturbance of weak power grid

The invention relates to a power system voltage control technology, in particular to a method and equipment for maintaining grid-connected point voltage three-phase balance under weak power grid unbalanced disturbance, and the method comprises the following steps: firstly, establishing a small signal model of a converter grid-connected system after unbalanced disturbance, and emphatically considering the phasing error influence of a phase-locked loop transient process; then, the fluctuation quantity of the amplitude and phase of the PCC voltage induced by unbalanced disturbance is accurately calculated, the influence is counteracted through a power outer ring feed-forward compensation mode, and three-phase balance of the PCC voltage in the transient state and the steady state process is achieved under the condition that the weak power grid unbalanced disturbance is maintained. According to the method, the influence of the machine-network interaction of the weak power grid on the dynamic characteristics of the PCC voltage is considered, and a better voltage balance maintaining effect is achieved in the weak power grid. Through composite control, according to PCC voltage vector amplitude and phase disturbance compensation, system transient state and steady state whole-process voltage balance maintenance after unbalanced disturbance is realized. The control structure is simple, and the robustness of the system is improved.
Owner:WUHAN UNIV

Power distribution network electric energy quality treatment method and device based on flexible multi-state switch

The invention relates to the technical field of electric power systems, in particular to a power distribution network electric energy quality treatment method and device based on a flexible multi-state switch, and the method comprises the steps: enabling the flexible multi-state switch FMS to be installed on a node in an electric power system according to an actual demand; according to the actual operation data of the three-phase unbalanced power system, a mathematical model of a power distribution network accessed to the FMS is established, the mathematical model of the power distribution network accessed to the FMS comprises an objective function, the objective function takes the minimum total network loss including line loss and FMS operation loss as a reference, and a control strategy and an operation mode of the flexible multi-state switch FMS are determined; the method is applied to FMS-based power distribution network optimization control. A simulation experiment is carried out in an IEEE 33-node power distribution network model, and the result shows that the FMS can effectively reduce the system network loss, improve the voltage level and improve the three-phase unbalance degree. The method provides powerful technical support for application of the flexible multi-state switch in an actual power system.
Owner:STATE GRID JIANGSU ELECTRIC POWER CO LTD NANTONG POWER SUPPLY BRANCH

Transformer parallel operation circulating current suppression method and system based on cloud edge collaborative architecture

The invention discloses a transformer parallel operation circulating current suppression method and system based on a cloud edge collaborative architecture, and relates to the technical field of power grid control, and the method comprises the steps: an edge node collects the multi-source dynamic data of a parallel transformer in real time, and constructs a local dynamic impedance model of a single transformer; the cloud receives the multi-modal data uploaded by each edge node, inputs the multi-modal data into an LSTM-SVM hybrid model trained based on a historical database, generates an impedance prediction weight of each edge node, and issues the impedance prediction weight to the corresponding edge node; the edge node receives the impedance prediction weight and injects the impedance prediction weight into a local dynamic impedance model to generate a corrected dynamic impedance matrix; and calculating a circulating current suppression instruction according to the corrected dynamic impedance matrix, and executing real-time regulation and control based on the circulating current suppression instruction. According to the method, the impedance prediction weight is generated through real-time collection of the edge nodes and calculation of the cloud, the local dynamic impedance model is effectively corrected, and then the circulating current suppression instruction is accurately calculated.
Owner:ELECTRIC POWER RES INST OF GUANGXI POWER GRID CO LTD

Intelligent three-phase imbalance treatment method

The invention relates to the technical field of intelligent operation of a power distribution network, in particular to an intelligent three-phase imbalance treatment method, which comprises the following steps of: firstly, acquiring three-phase current, three-phase voltage and electrical characteristic quantity of each single-phase load, and carrying out commutation adaptability evaluation on the load based on a real-time power factor, a current harmonic distortion rate and a load power flow direction; and calculating the three-phase unbalance degree of each power supply branch, identifying an extreme branch with the unbalance degree exceeding the standard, and screening out loads with optimal commutation adaptability parameters to form a candidate load set. And generating a commutation priority sequence for the candidate load through a historical commutation frequency and real-time contribution degree two-factor model. And triggering zero-millisecond seamless commutation under the conditions of meeting a safe voltage threshold and equal voltage time, verifying a switching result after commutation, limiting the number of commutation times of single treatment, and monitoring the three-phase unbalance degree in real time until the three-phase unbalance degree is recovered to a qualified range. According to the invention, the accuracy and safety of the commutation decision can be improved, and the dynamic balance adjustment of the three-phase load is realized.
Owner:ZHEJIANG XIANHENG INT GENERAL EQUIPCO

Three-phase balance user phase adjustment method based on multi-objective optimization control

The invention provides a three-phase balance user phase adjustment method based on multi-objective optimization control, and relates to the technical field of power system control. According to the technical scheme provided by the invention, after the phase distribution results under different constraint conditions are calculated, the problem of deterioration of other indexes possibly caused by single target optimization can be avoided by constructing the multi-objective function containing the indexes. And meanwhile, multi-objective function value calculation and comparison are carried out on each phase distribution scheme, and the phase distribution scheme with the minimum multi-objective function value is selected as the optimal scheme, so that the overall optimality and the balance of each technical index can be considered. Compared with a phase adjustment mode in which only a single-phase meter or a three-phase meter is considered in the prior art, the phase adjustment scheme provided by the invention adopts a multi-objective function to realize trade-off optimization among indexes for the condition that the single-phase meter and the three-phase meter exist at the same time, so that accurate phase adjustment can be realized, and the load balancing effect is improved.
Owner:HANGZHOU ZHICHENG ELECTRONIC TECH CO LTD

Multi-module parallel balance coordination control method, device, equipment and storage medium

The invention relates to a multi-module parallel balance coordination control method, device and equipment and a storage medium, and the method comprises the following steps: carrying out the time sequence decoupling analysis of a multi-module parallel network based on original state data, and obtaining a relative state feature set between modules; if the relative state feature sets are not in respective preset state ranges, performing load balancing coordination analysis on the multi-module parallel network based on the relative state feature sets through a Lagrange multiplier method to obtain a load balancing coordination distribution scheme; performing control instruction conversion on the load balancing coordination distribution scheme to obtain a control instruction sequence of each module; and analyzing the control instruction sequence and implementing the control instruction sequence to each module so as to realize load balancing of the multi-module parallel network, thereby solving the technical problem that the condition of uneven load distribution is aggravated due to the fact that a traditional method may not timely respond when the power grid condition fluctuates or the load suddenly changes.
Owner:SHENZHEN YILANCO ELECTRIC CO LTD